public void AddElement(IComparable key, object data)
{
if (key == null)
{
throw new ArgumentNullException("key");
}
if (data == null)
{
throw new ArgumentNullException("data");
}
TreeItem newItem = CreateItem(key, data);
TreeItemProxy root = _retriever.GetRoot();
if (root == null)
{
TreeItemProxy newItemProxy = _retriever.CreateItemProxy(newItem);
_retriever.SetRoot(newItemProxy);
}
else
{
TreeItemProxy insertElement = root.GetParentElement(key);
TreeItemProxy newItemProxy = _retriever.CreateItemProxy(newItem);
if (key.CompareTo(insertElement.Item.Key) < 0)
{
insertElement.LeftChild = newItemProxy;
}
else
{
insertElement.RightChild = newItemProxy;
}
}
}
public void ShowStructure()
{
TreeItemProxy tip = _retriever.GetRoot();
if (tip.Item == null)
{
Console.WriteLine("empty");
}
else
{
StringBuilder sb = new StringBuilder();
sb.Append("Root = " + tip.Item.Key.ToString() + "\r\n");
tip.ShowStructure(sb);
Console.WriteLine(sb.ToString());
}
}
public void RemoveElement(IComparable key)
{
TreeItemProxy root = _retriever.GetRoot();
if (root == null)
{
throw new ArgumentException("key does not exist");
}
TreeItemProxy tip = root.GetElement(key);
if (tip == null)
{
throw new ArgumentException("key does not exist");
}
// Make element leaf
if (tip.LeftChild != null)
{
TreeItemProxy swapElement = tip.LeftChild;
while (swapElement.RightChild != null)
{
swapElement = swapElement.RightChild;
}
SwapElements(tip, swapElement);
}
else
if (tip.RightChild != null)
{
TreeItemProxy swapElement = tip.RightChild;
while (swapElement.LeftChild != null)
{
swapElement = swapElement.LeftChild;
}
SwapElements(tip, swapElement);
}
}
private TreeItemProxy _root; // null if not set
public InMemoryTreeItemRetriever()
{
// An in-memory tree is always empty on start
_root = null;
}
public void SetRoot(TreeItemProxy rootItem)
{
_root = rootItem;
}
public TreeItemProxy(TreeItem item, TreeItemProxy parent, bool isLeftChild)
{
this._item = item;
this._isLeftChild = isLeftChild;
}
public void SetRoot(TreeItemProxy rootItem)
{
// TODO: Add DiskTreeItemRetriever.SetRoot implementation
}
public void SwapElements(TreeItemProxy innerNode, TreeItemProxy leaf)
{
}